Inundações urbanas no semiarido nordestino: o caso da cidade de Pau dos Ferros - RN

The Apodi river basin, particularly within the snippet that crosses Pau dos Ferros - RN city, place anthropogenic actions that interfere in the dynamic environment by modifying the local landscape. The reflection of these actions can be seen in the floods that occur in rainy periods (February to may) virtually every year in the city. It is important to stress that the project of integration of the waters of the San Francisco basin with the northern basin of Northeastern will perennial the main channel of the river basin, and generate greater impacts in the region. This work sought to define a methodology able to delimit areas susceptible to flooding in cities of semiarid Northeast based on the Pau dos Ferros RN city. The dissertation is divided into two chapters and introduction. The introduction presents a theoretical frame based on discussion of the concept of risk, their main characteristics and subdivisions; floods; geotecnologies; Apodi River basin; municipal data Pau dos Ferros RN and design integration of Francisco basin with the northern basins Northeast. The first chapter evaluates the urban expansion process between 1987 and 2008, delimiting the flood areas and analyzes the relationship between urban growth and retention areas. The second chapter identifies the flood risk areas in the Pau dos Ferros city. The methodology used was based on tools of geographic information system GIS from software SPRING/INPE 5.1, as well as bibliographical, satellite images, aerial photographs and field activities. The results obtained enabled view the rapid expansion of the urban area of Pau dos Ferros, which has doubled in a period of 22 years. The population density checks with greater intensity in South-central portion of the city, in flood areas and not flood (Cap. 01). It was noted also that some neighborhoods along the River Apodi are susceptible to more instances of flooding ranging from minimum to maximum, while in neighborhoods near the Riacho Cajazeiras floods occur to a lesser extent because of altimetry higher and lower water volume. (Cap. 02). It is expected that this work will help in the preparation of flood risk municipal map subsidising managers in implementing public policies targeted to the softening of urban flood-related issues in Pau dos Ferros RN and serve as a model for mapping of other cities with similar characteristics analyzed in this work

Evolução geodinâmica e condicionamento estrutural dos terrenos Piancó-Alto Brígida e Alto Pajeú, domínio da zona transversal, NE do Brasil

This thesis aims to advance in the geological knowledge of the region comprising the Piancó-Alto Brígida (TPAB) and Alto pajeú (TAP) terranes, in the Transversal Zone Domain (Borborema Province, NE Brazil), with the main objective of understanding the geodynamic evolution and the structural framework of these units. To reach this objective, and besides field work and interpretation of traditional aerial photographs, other tools were employed like of remote sensing products (Landsat 7 ETM+, aeroradiometrics, aeromagnetics and topographical images), lithogeochemical (whole rock) analyses and geochronological dating (U-Pb in zircon), besides integration with literature data. In the area, several precambrian geological units outcrop, represented in the TAP by the paleoproterozoic Serra Talhada and Afogados da Ingazeira complexes, Riacho Gravatá Complex (metavolcano-sedimentary sequence of Stenian-Tonian age) and Cariris Velhos orthogneisses (of Tonian age). The TPAB comprises the Santana do Garrote (lower unit) and Serra do Olho d'Água (upper unit) formations of the Cachoeirinha Group (Neoproterozoic III), besides the Piancó orthogneisses and Bom Jesus paragneisses; the latter correspond to an older (basement ?) block and a possible high grade equivalent of the Cachoeirinha Group (or Seridó Group ?), respectively. Several Brasiliano-age plutons occur in both terranes.The aeromagnetic data show the continuity, at depth, of the main shear zones mapped in the region. The Patos, Pernambuco, Boqueirão dos Cochos, Serra do Caboclo, Afogados da Ingazeira/Jabitacá and Congo-Cruzeiro do Nordeste shear zones reach depths greater than to 6-16 km. The aeromagnetic signature of other shear zones, like the Juru one, suggests that these structures correspond to shallower crustal features. The satellite images (Landsat 7 ETM+) and aerogamaspectrometric images discriminate different geological units, contributing to the mapping of the structural framework of the region. The Serra do Caboclo Shear Zone was characterized as the boundary/suture between the TPAB and TAP. This structure is an outstanding, pervasive feature that separates contrasting geological units, such as the Neoproterozoic III Cachoeirinha Group in the TPAB and the Riacho Gravatá Complex and the Cariris Velhos metaplutonics, of Stenian-Tonian age, in the TAP. Occupying different blocks, these units are not found in authoctonous relations, like unconformities and intrusive contacts. Concerning the Cariris Velhos (ca. 1,0 Ga old) event is recorded by radiometric ages of the Riacho Gravatá Complex metavolcanics and intrusive augen and orthogneisses, all of them displaying geochemical affinities of arc or collisional settings. A structural signature of this event was not recorded in the region, possibly due to its low grade/low strain style, obliterated by the overprinting of younger, higher grade/high strain Brasiliano-age fabrics.The first tectonic event (D1) observed in the Cariris Velhos lithotypes presents contractional kinematics with transport to the NW. Neoproterozoic III geochronologic dates, obtained in late-D1 granitoids, imply a Brasiliano age (ca. 610-600 Ma) for this deformation event. The second tectonic event (D2) characterized in the region corresponds to the Brasiliano transcurrent kinematics of the outstanding shear zones and associated granitoid plutons. The geochronological (U-Pb in zircon) data obtained during this thesis also confirms the occurrence of the Cariris Velhos magmatic suite in the TAP, as well as the Neoproterozoic III age to the Cachoeirinha Group in the TPAB. The TAP (Riacho Gravatá Complex, augen and orthogneisses) is interpreted as a continental arc possibly accreted to a microcontinent during the Cariris Velhos (Stenian-Tonian) event. Later on, this terrane collided with the TPAB at the beginning of the Brasiliano orogeny (D1 contractional deformation), and both domins were reworked by the transcurrent shear deformation of the D2 event

Análise de risco à erosão costeira na região de Tibau do Sul/RN através de mapeamento geoambiental e análise morfodinâmica

The research area is located on the county of Tibau do Sul, in the east coast of Rio Grande do Norte State, about 80km south of the capital Natal. The tourism represents the main income activity and Pipa beach is the most visited beach in the city, annually receives a large influx of domestic and foreign tourists. Some recent studies have reported the occurrence of coastal erosion in this littoral, being the main objective of the research, analyze the existing coastal erosion, through two methodologies, the geoenvironmental mapping and beach morphodynamics. The geoenvironmental mapping was done from oblique aerial photographs and field visits, which sought to carry out first the geomorphological mapping, with the purpose of analyzing features that suggest susceptible areas to erosion, as areas without protection of natural dunes, marine terraces, or sandstones (beach-rocks and ferruginous sandstones), areas with the presence of gullies and stretches where the sea-cliffs were in direct contact with the action of the sea, representing the beginning of the beach profile. In the morphodynamic study sought to carry out the survey of the physical and morphological characteristics, the analysis of sediment grain of the beaches and finally the analysis of the morphodynamic parameters to generate a table of risk to erosion by sector of the beach. The morphodynamic parameters were defined by the methodology proposed by Short (2006), in which considers different patterns of dynamism on beaches with characteristics favorable and unfavorable to erosive profiles. The maps indicated different levels of risk to the segments of the beaches analyzed, suggesting risk to erosion low and low to moderate only in areas north and northwest of the beaches of Madeiro and Curral, and levels of moderate and high risk sectors in the south and southeast of these beaches . The beach of Pipa showed moderate levels of risk and moderate to high at the ends and high risk to erosion in the central portion. The study of the coastal environment, its morphological evolution, and areas with problems of erosion, are of fundamental importance to assist coastal management policies, giving grants for planning activities undertaken in these regions

Sistemas orbitais e aéreos aplicados à análise multi-escala da tectônica rúptil atuante na borda sudeste da Bacia do Parnaíba

The tectonics activity on the southern border of Parnaíba Basin resulted in a wide range of brittle structures that affect siliciclastic sedimentary rocks. This tectonic activity and related faults, joints, and folds are poorly known. The main aims of this study were (1) to identify lineaments using several remotesensing systems, (2) to check how the interpretation based on these systems at several scales influence the identification of lineaments, and (3) to contribute to the knowledge of brittle tectonics in the southern border of the Parnaíba Basin. The integration of orbital and aerial systems allowed a multi-scale identification, classification, and quantification of lineaments. Maps of lineaments were elaborated in the following scales: 1:200,000 (SRTM Shuttle Radar Topographic Mission), 1:50,000 (Landsat 7 ETM+ satellite), 1:10,000 (aerial photographs) and 1:5,000 (Quickbird satellite). The classification of the features with structural significance allowed the determination of four structural sets: NW, NS, NE, and EW. They were usually identified in all remote-sensing systems. The NE-trending set was not easily identified in aerial photographs but was better visualized on images of medium-resolution systems (SRTM and Landsat 7 ETM+). The same behavior characterizes the NW-trending. The NS-and EW-trending sets were better identified on images from high-resolution systems (aerial photographs and Quickbird). The structural meaning of the lineaments was established after field work. The NEtrending set is associated with normal and strike-slip faults, including deformation bands. These are the oldest structures identified in the region and are related to the reactivation of Precambrian basement structures from the Transbrazilian Lineament. The NW-trending set represents strike-slip and subordinated normal faults. The high dispersion of this set suggests a more recent origin than the previous structures. The NW-trending set may be related to the Picos-Santa Inês Lineament. The NS-and EW-trending sets correspond to large joints (100 m 5 km long). The truncation relationships between these joint sets indicate that the EW-is older than the NS-trending set. The methodology developed by the present work is an excellent tool for the understanding of the regional and local tectonic structures in the Parnaíba basin. It helps the choice of the best remote-sensing system to identify brittle features in a poorly known sedimentary basin

Evolução espaço-temporal da ocupação urbana sobre áreas naturais no município de Natal-RN

In this work the landscape morphodynamics was used to check the strength and importance of the changes carried out by man on the environment over time, in Natal-RN municipality. The occupation of partially preserved natural areas was analyzed, but environmentally fragile, such as riparian forests, vegetation on the banks of waterways, which play regulatory role of the water flow, and the dunes, which guarantee the rapid recharge of aquifers. The impacts of urban sprawl in Natal Southern and West zones Were identified and characterized, through a detailed mapping in the period between 1969 and 2013 the main Permanent Preservation Areas - PPA (banks of rivers and lagoons, and dunes remaining) and their temporal changes. For this were used aerial photographs and satellite imagery, altimetry data, and pre-existing information, which allowed the creation of a spatial database, and evolution of maps of impervious areas, evolution of the use and occupation and Digital Terrain Model (DTM) from contour lines with contour interval of 1 meter. Based on this study presents a diagnosis of the environmental situation and the state of conservation of natural areas, over the last 44 years, compared to human pressures. In general, it was found that the urban settlement has advanced about 60% of studied natural areas. This advance was growing by the year 2006, when there was a slowdown in the process, except for the Environmental Protection Zone (EPZ) 03, where the river Pitimbú and your PPA, which experienced a more significant loss area. The urban occupation affected the natural drainage and contributed to the contamination of groundwater Natal, due to increased sealed area, the release of liquid and solid waste, as well as the removal of riparian vegetation. Changed irreversibly the natural landscape, and reduced the quality and quantity of water resources necessary for the population. Thus, it is necessary to stimulate the adoption of use and protection of PPA planning measures, to the preservation of the San Valley Region inserted into the EPZ 01, and integrate more remaining dunes, in good condition, this EPZ, due to the importance of those remaining on the environment and the maintenance of quality of life. It is suggested, also, protection of catchment areas, such as PPA ponds and Pitimbú River. Finally, it is expected that this study can assist the managers in making decisions in urban and environmental planning of the municipality

Unidades geoambientais e áreas de preservação permanente como instrumentos de auxílio para o planejamento ambiental - o caso da via costeira de Natal-RN

Brazilian law provides a series of rules and policies which regulate space use and occupancy as well as guide environmental planning. Among those are the Permanent Preservation Areas (PPAs) which purpose is to ensure the preservation of elements that are essential to maintain the environmental function and landscape. Another important instrument identifier of spaces are geoenvironmental units, which are synthesis elements grouping areas of similar characteristics and can be used for the analysis of risk, fragility and potential use of spaces. The geoenvironmental units are defined by more complex processes (information integration), focusing not only on individual elements, but being determined from a systemic analysis. Is It possible to identify and delineate APPs from the identification and determination of geoenvironmental units? The aim of this study was to evaluate the potential of geoenvironmental units in the process of identification and delineation of APPs a see how much of the study area, the area by the Coast line in Natal/RN, is still good for occupation. It was used the physiognomic method, in which the limits of the units are plotted on a synthetic document (aerial photographs), valuing aspects of relief in a range of detail by the analysis of systemic categories (element, structure, function and interaction), observed. The methodology used allowed the identification and delineation of eleven geoenvironmental units and, from these, it was possible to identify and delineate four out of the five PPAs occurring in the study area. Only a small space of 1.2 ha of the study area is not considered APP by law. Thus, the occupation of the unoccupied area by the Coast line is not feasible from a legal standpoint. The geoenvironmental units as well as the identified and delineated APPs in the area by the Coast line are spaces which preservation is guaranteed by law in various scopes and are necessary to maintain the environmental functions of the area. The planning for the use and occupation of the area should involve the recovery of degraded areas and the creation of elements that make possible the use as well as attract the community, as provided in the initial planning, by ensuring the public utility and social interest in the Project.

Uso e ocupação do solo e a transformação da paisagem na faixa litorânea da Via Costeira, município de Natal/RN

The coastal area of the city of Natal due to its location and natural potentialities has been an area where we have experienced big changes in its environment, at the expense of several forms of use and human occupation. On the coast of Via Costeira beach the process of use and land occupation was structured at the end of 1970s and early 1980s, as a result of the government policy which has developmental essence, based on the settlement of plenty big enterprises by the Parque das Dunas/Via Costeira Project. This project was created to install in Natal, capital of the state, infrastructure equipment on this stretch of coastline consisted of dune fields and many parts of ecosystems which have high natural relevance and fragility that used to present a semi-isolation in the urban city, for the development of tourist activities, which is considered as a viable economic solution capable of setting right serious socioeconomic problems that had persisted there. According to what was said so far, this study aimed to analyze the forms of use and land occupation besides the change of the landscape along the Via Costeira coast in the city of Natal/RN. These changes often take place without considering the complexity and fragility of natural ecosystems involved. The geoenvironmental study was based on the geosystemic theory, thus It was possible to analyze the human interventions in the superficial aspects of landscapes holistically. The practical procedures were contemplated with literature searches, followed by field work where were fulfilled the recognition and general characterization of the area in order to investigate and analyze the main types of land occupation and its use that have taken place there since big buildings began to come out, being supported by the legislation whose laws are about protection and conservation of coastal natural resources. The research also includes the identification and evaluation of the main types of negative impacts caused due to different forms of use that induce environmental and social conflicts nearby this shore. Thus, It was carried out a spatial and multitemporal analysis from orthophotos, aerial photographs and others taken during the field work besides satellite images too. The information which is taken out from these instruments was used to draw maps related to land occupation, spatial impacts and other thematic maps. We worked on a hypothesis that the implementation of mega enterprises on Via Costeira and many different forms of intensified use by human actions, has not considered the natural aspects and restrictions of use in this area, these ones would be the main factors that brought on the suppression and degradation in this environment and consequently the transformation of the natural landscape.